608 research outputs found

    Can crop disease control cope with climate change?

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    Crop yields need to increase by at least 70% over the next 35 years in order to meet the global demands for food due to the increasing population and changing dietary preferences towards meat and dairy products in developing nations. Climate change threatens food security because pests and diseases that limit crop productivity are all sensitive to climate change and especially to more frequent extreme weather events. A more variable climate will mean greater uncertainty for crop yields because crop development stages, e.g. when reproductive organs such as flowers and seeds are produced, are especially vulnerable to short periods of extreme temperature or drought. For instance, Europe experienced an extreme climate event during the summer of 2003 when temperatures were ca. 6°C higher and rainfall was ca. 300 mm less than the long-term mean values. One impact of this summer was a record crop yield decrease of ca. 36% below average yield in Italy for maizePeer reviewedFinal Accepted Versio

    Evaluation of oilseed rape seed yield losses caused by Leptosphaeria biglobosa in central China

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    This document is the Accepted Manuscript version of the following article: Xiang Cai, Yongju Huang, Daohong Jiang, Bruce D. L. Fitt, Guoqing Li, and Long Yang, "Evaluation of oilseed rape seed yield losses caused by Leptosphaeria biglobosa in central China", European Journal of Plant Pathology, first published 9 June 2017. Under embargo. Embargo end date: 9 June 2018. The final publication is available at Springer via: http://dx.doi.org/10.1007/s10658-017-1266-x.Phoma stem canker of oilseed rape (Brassica napus), caused by Leptosphaeria maculans/L. biglobosa is a globally important disease. Severe phoma stem canker symptoms have been observed on winter oilseed rape in China but the seed yield loss caused by this disease remains unknown. In May 2012 and May 2013, 17 and 13 crops were surveyed, respectively, in seven counties of Hubei Province, central China. Stems with phoma stem canker disease symptoms were sampled for pathogen isolation and identification. Only L. biglobosa was identified by culture morphology and species-specific PCR; no L. maculans was found. To evaluate the yield losses, yield components (number of branches per plant, number of pods per plant, 1000-seed weight, number of seeds per pod) were assessed on healthy and diseased plants sampled from crops in four counties and on plants from inoculated pot experiments (plants of three cultivars were inoculated at the green bud stage by injecting L. biglobosa conidia into the stem between the first and second leaf scars). Results of the field surveys showed that diseased plants had 14–61% less branches and 32–83% less pods than healthy plants, respectively. The estimated seed yield loss varied from 10% to 21% and from 13% to 37% in 2012 and 2013, respectively. In the pot experiments, there were no differences in numbers of branches or pods but there were differences in number of seeds per pod between inoculated and control plants. For the three cultivars tested, the inoculated plants had yield losses of 29–56% compared with the control. This study indicates that L. biglobosa could cause substantial seed yield loss in China.Peer reviewedFinal Accepted Versio

    Diseases of winter linseed : occurrence, effects and importance

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    In 1998, a survey of the incidence and severity of diseases was carried out on 30 crops of winter linseed at early flowering and again at crop maturity. Five crops each were selected in south west, east, east Midlands, west Midlands and north of England and from Scotland. Crops were predominantly cv. Oliver (90% crops), grown from certified seed (83%) and sown in September (97%). Pasmo (Mycosphaerella) was the most important disease, affecting leaves of 73% crops at early flowering and 90% crops at maturity. Powdery mildew (70% crops), Alternaria (30% crops) on leaves and Botrytis on capsules (70% crops) were also common. Regional differences were apparent for powdery mildew, which was present in all regions except the southwest, whilst Alternaria predominated in the Midlands. Half of the crops surveyed had received fungicide sprays, but this appeared to have made limited impact on disease severity. Pasmo is a new threat to UK linseed crops and this raises concerns about the threat it poses to spring linsee

    Comparative biology of different plant pathogens to estimate effects of climate change on crop diseases in Europe

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    This review describes environmental factors that influence severity of crop disease epidemics, especially in the UK and north-west Europe, in order to assess the effects of climate change on crop growth and yield and severity of disease epidemics. While work on some diseases, such as phoma stem canker of oilseed rape and fusarium ear blight of wheat, that combine crop growth, disease development and climate change models is described in detail, climate-change projections and predictions of the resulting biotic responses to them are complex to predict and detailed models linking climate, crop growth and disease development are not available for many crop-pathogen systems. This review uses a novel approach of comparing pathogen biology according to 'ecotype' (a categorization based on aspects such as epidemic type, dissemination method and infection biology), guided by detailed disease progress models where available to identify potential future research priorities for disease control. Consequences of projected climate change are assessed for factors driving elements of disease cycles of fungal pathogens (nine important pathogens are assessed in detail), viruses, bacteria and phytoplasmas. Other diseases classified according to 'ecotypes' were reviewed and likely changes in their severity used to guide comparable diseases about which less information is available. Both direct and indirect effects of climate change are discussed, with an emphasis on examples from the UK, and considered in the context of other factors that influence diseases and particularly emergence of new diseases, such as changes to farm practices and introductions of exotic material and effects of other environment changes such as elevated CO 2. Good crop disease control will contribute to climate change mitigation by decreasing greenhouse gas emissions from agriculture while sustaining production. Strategies for adaptation to climate change are needed to maintain disease control and crop yields in north-west Europe.Peer reviewe

    Counting the cost of preventable diabetes-related lower limb amputations at a single district hospital in KwaZulu-Natal: what does this mean, what can be done?

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    Background: Healthcare policy decisions are driven by many factors, including cost, hence the need to show costs of diabetes mellitus-related lower limb amputations (DMLLA) to inform amendments to health care. Substantial decreases in amputation rates are associated with specialised podiatry foot clinics and ongoing foot education, as per national guidelines on the multidisciplinary team approach (MDTA) to diabetes health care. There are only two podiatry posts in KwaZulu-Natal (KZN) state health department (DoH).Objectives: Aims were to draft the medical costs for 660 DMLLA at Greys Hospital for the period 2013–2017; to extrapolate costs on annual DMLLA in KZN; to outline socio-economic costs for future investigation; to present evidence that podiatry in the MDTA can decrease numbers of DMLLA.Methods: A retrospective review on clinical data captured in real time and maintained by the Pietermaritzburg Metropolitan Trauma Service (PMTS) and Surgical Service (PMSS) was performed. Costs were analysed on data for 660 patients’ DMLLA at Greys Hospital between 2013 and 2017, and psychological and socio-economic costs via literature review.Results: Medical care at Greys Hospital for 660 DMLLA in the five years cost in excess of ZAR 213 million. Extrapolated to the 1 231 diabetic amputations (2014) equals an annual cost to KZN DoH in excess of ZAR 398 million. Personal, family loss and socio-economic costs are estimated in excess of ZAR five million per amputee, resulting in further cost of ZAR 6.155 billion per annum to KZN. Extrapolation across 11 provinces signifies a national cost of at least ZAR 68 billion.Conclusions: We present a gauge of the cost of DMLLA to KZN and national health. Substantial possible socio-economic losses compound these. The role of podiatrists within MDTA teams has an evidence base to prevent DMLLA

    Validating the utilisation of venous bicarbonate as a predictor of acute kidney injury in crush syndrome from sjambok injuries

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    Background. Crush injury secondary to sjambok beatings is a well-described phenomenon in southern Africa. Owing to a number of factors, it can result in acute kidney injury (AKI). In 1992, Muckart et al. described a risk stratification system using venous bicarbonate (VB) that can be used in the management of these patients.Objective. To validate this score in the modern era of AKI risk stratification.Methods. A retrospective study was performed on a local trauma database from June 2010 to December 2012. All patients with crush injury from sjambok/blunt instrument beatings were included in the analysis. VB was compared with the Kidney Disease Improving Global Outcomes scoring system for AKI. Serum base excess (BE) and creatine kinase were also examined as biomarkers. The endpoints were the need for renal replacement therapy (RRT) and mortality.Results. Three hundred and ten patients were included. The overall mortality rate was 1.9%, 14.8% of patients had AKI, and 3.9% required RRT. Both VB and BE performed well in RRT prediction, with areas under the receiver operating characteristic curve of 0.847 (95% confidence interval (CI) 0.756 - 0.938; p<0.001) and 0.871 (95% CI 0.795 - 0.947; p<0.001), respectively. The sensitivity and specificity of BE were 83.3% and 80.2% at an optimal cut-point of –7.25 mmol/L, while those of VB were 83.3% and 79.5% at an optimal cut-point of 18.85 mmol/L. VB was significantly different across the AKI risk groups (p<0.001), in keeping with the original Muckart risk stratification system.Conclusion. The risk stratification score using VB is valid and should continue to be used as a tool in the management of patients with sjambok injuries. BE performs well in predicting the need for RRT, with a value of <–7.25 mmol/L indicating severe injury

    Controlling crop disease contributes to both food security and climate change mitigation

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    Original article can be found at: http://www.tandfonline.com/ Copyright Taylor & FrancisGlobal food security is threatened by crop diseases that account for average yield losses of 16 per cent, with the greatest losses experienced by subsistence farmers in the developing world. Climate change is exacerbating the threats to food security in such areas, emphasizing the need to increase food production in northern European countries such as the UK. However, the crops must be grown in such a way as to minimize greenhouse gas (GHG) emissions associated with their production. As an example, it is estimated that production of UK winter oilseed rape is associated with GHG of 3300 kg CO2 eq. ha(-1) of crop and 834 kg CO2 eq. t(-1) of seed yield, with 79 per cent of the GHG associated with the use of nitrogen fertilizer. Furthermore, it is estimated that control of diseases by use of fungicides in this UK oilseed rape is associated with a decrease in GHG of 100 kg CO2 eq. t(-1) of seed. Winter oilseed rape cultivar disease resistance is associated with a decrease in GHG of 56 kg CO2 eq. t(-1), although this figure is an underestimate. These results demonstrate how disease control in arable crops can make a contribution to both climate change mitigation and sustainable arable crop production to ensure global food security.Peer reviewe

    The spectrum and outcome of paediatric traumatic brain injury in KwaZulu-Natal Province, South Africa has not changed over the last two decades

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    Objectives. This retrospective review of a prospectively entered and maintained hybrid electronic trauma registry was intended to develop a comprehensive overview of traumatic brain injury (TBI) in children and adolescents and to compare it with previous audits from our local environment and from other developing world centres. All TBI patients admitted to hospital were included in this study. We reviewed the age, gender, outcomes, radiological findings and treatment of the patients.Methods. All patients aged ≤18 years old who were admitted by the Pietermaritzburg Metropolitan Trauma Service (PMTS) with TBI between December 2012 and December 2016 were included in this audit.Results. During the 4-year period under review, a total of 563 children and adolescents were treated for TBI by the PMTS. The median age was 6.4 years and 29% (n=165) were females. The mechanism of TBI was blunt trauma in 96% (n=544) of cases, with 4% (n=19) suffering penetrating trauma. The penetrating mechanisms included impalement by a cow horn and miscellaneous injuries due to saws, axes, barbed wire, spades, stones and knives. The blunt mechanisms included falls (n=102), assaults (n=108), collapse of a building (n=28), bicyclerelated injury (n=14), falling off a moving vehicle (n=280), motor vehicle accident (MVA; n=59), pedestrian vehicle accident (PVA; n=183) and animal-related injuries (n=8). There were 454 (80%) mild, 67 (12%) moderate and 42 (7%) severe cases of TBI. A total of 48 patients were admitted to the intensive care unit and 23 were admitted to the high care unit. Nine patients died. All the deaths were in the MVA and PVA group. The spectrum of TBI as diagnosed on computed tomography scans was nonspecific cerebral contusion (n=92), depressed skull fracture (n=70), sub-arachnoid haemorrhage (n=60), extradural haemorrhage (n=41), intracerebral haemorrhage (n=19), free air (n=19),subdural haemorrhage (n=13), intraventricular haemorrhage (n=9). A total of 62 (11%) patients required surgery.Conclusion. There is a significant burden of paediatric TBI in Pietermaritzburg. The majority of TBI was related to blunt trauma and assaults were very common. Although the short-term outcomes are good, the long-term consequences are poorly understood. Injury prevention programmes are needed to help reduce this burden of disease and a nationwide trauma registry is long overdue

    Validation of the Simplified Motor Score in patients with traumatic brain injury at a major trauma centre in South Africa

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    Background. This study used data from a large prospectively entered database to assess the efficacy of the motor score (M score) component of the Glasgow Coma Scale (GCS) and the Simplified Motor Score (SMS) in predicting overall outcome in patients with traumatic brain injury (TBI).Objective. To safely and reliably simplify the scoring system used to assess level of consciousness of trauma patients in the acute setting.Methods. A retrospective observational review of the Pietermaritzburg Metropolitan Trauma Service hybrid electronic medical registry database was performed during the period January 2013 - December 2015. Patients were classified into three groups using their GCS as an injury severity score. These were mild TBI (GCS 13 - 15), moderate TBI (GCS 9 - 12) and severe TBI (GCS <9). The Glasgow M score was specifically evaluated to determine the relationship between the individual motor component and patient outcome.Results. GCS scores and M scores were analysed in a total of 830 patients. There was a decline in survival rate when the M score on admission was ≤4. The decline was more significant when the M score was ≤3. Survival rates were 26.8% (11/41) for patients with an M score of 1, 63.6% (14/22) for those with a score of 2, 56.5% (13/23) for those with a score of 3, 80.0% (20/25) for those with a score of 4, and 95.5% (121/128) for those with a score of 5. Of 591 patients with an M score of 6, 580 (98.1%) survived. Mortality rose dramatically with declining SMS. This was highly significant. When the M score was plotted against mortality in 830 patients, there was a correct prediction in 769 cases (accuracy 92.7%, sensitivity 67.6%, specificity 95%). The area under the receiver operating characteristic (ROC) curve was 0.9037, with a standard deviation (area) of 0.0227. When comparing the SMS against mortality, the accuracy was 77.1%, the sensitivity 84.5% and the specificity 76.4%. The fitted ROC area was 0.891 and the empirical ROC area 0.86.Conclusion. The M score component of the GCS and the SMS accurately predict outcome in patients with TBI. In cases where the full GCS is difficult to assess, the M score and SMS can be used safely as a triage tool

    Identification of environmentally stable QTL for resistance against Leptosphaeria maculans in oilseed rape (Brassica napus)

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    © The Author(s) 2015. This article is published with open access at Springerlink.com. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Phoma stem canker, caused by Leptosphaeria maculans, is a disease of world-wide importance on oilseed rape (Brassica napus). Quantitative trait locus (QTL) mediated resistance against L. maculans in B. napus is considered to be race non-specific and potentially durable. Identification and evaluation of QTL for resistance to L. maculans is important for breeding oilseed rape cultivars with durable resistance. An oilseed rape mapping population was used to detect QTL for resistance against L. maculans in five winter oilseed rape field experiments under different environments. A total of 17 QTL involved in ‘field’ quantitative resistance against L. maculans were detected and collectively explained 51% of the phenotypic variation. The number of QTL detected in each experiment ranged from two to nine and individual QTL explained 2 to 25% of the phenotypic variation. QTL × environment interaction analysis suggested that six of these QTL were less sensitive to environmental factors, so they were considered to be stable QTL. Markers linked to these stable QTL will be valuable for selection to breed for effective resistance against L. maculans in different environments, which will contribute to sustainable management of the disease.Peer reviewe
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